1. Field of the Invention
The present invention relates to communication systems; more particularly, controlling traffic in communication systems.
2. Brief Description of the Related Art
FIG. 1 illustrates a typical communication system. The communication system consists of network elements or components 10, 12, 14 and 16. The network elements (NEs) each communicate with a central system control function component (SCF) 18. Central system control function 18 coordinates traffic between the network elements and may be, for example, a network signaling center or a traffic routing node. In the case of a wireless communication system, the network elements may be, for example, mobile switching centers (MSCs) or base stations. Additionally, wireless communication systems include components such as home location register (HLR) 20 and wireless network point (WNP) 22. The home location register is used, for example, to authenticate the identity of mobiles requesting access to the network, and wireless network point 22 may be a wireless base station or an access point in a wireless local area network.
The SCF controls its workload by controlling the communications between it and each of the network elements. For example, if SCF 18 is overloaded by communications from a particular network element, such as network element 12, it may send an ACG (automatic code gapping) message or block command to network element 12. The AGC message commands network element 12 to stop sending messages to SCF 18 for a specified length of time. The ACG message is known as a automatic code gapping message in networks using the ANSI-41 communication protocol. In addition to the SCF becoming overloaded, it is possible for a network element such as network element 16 to become overloaded. In this case, network element 16 simply stops accepting communications from the SCF in order to reduce its workload. Unfortunately, SCF 18 and any network element or component trying to communicate with network element 16, is not informed of the overload condition at network element 16. This results in network element 16 ignoring messages sent from other elements or components within the network while the elements or components sending the messages are operating under the assumption that network element 16 is receiving and responding to messages sent.